Real-Time Physics Simulation Forum

You need to set the restitution values for the static objects too. The default value is 0 which means no bounce.

When colliding, the restitution values for the two colliding bodies is combined by multiplication, so if one of them is zero, the result is zero, no matter what the other value is.

Hi Erwin!

Yes that fixed it Thanks for the swift fix!

Ola

It's velocities. When the rigid body moves slower than the threshold value, it goes to sleep.

If your units are meters, then the linear part is in meters/second. The angular bit is in rad/s.

Best regards,
Ola

Hi, I just installed Bullet from SVN on a new mac, and built it in double-precision mode. It seems that the collision detection is not working at all. For example, shooting boxes in any demo makes them just fly through everything. Single-precision mode works just fine, by the way. I compared by buil...

For the cell's shell you'll have to use some shape that is hollow, so the only thing I can think of is a mesh shape. The mesh triangles are double sided and "paper thin". If the cell body is static, you can use the btBvhTriangleMeshShape. (if you want it dynamic, maybe the btConvexTriangle...

I use the btBvhTriangleMeshShape for my terrain system. The terrain is divided into tiles that are 4x4 km each, with one shape for each. This way I can load terrain on demand (add/remove tiles). So I'm not sure you really have to create your own concave shape, the Bvh shape is pretty fast for static...

It's recommended to upload the patch to the issue tracker at http://code.google.com/p/bullet/issues/list.

Great work!

Yes it's recommended to submit patches there, so they won't get lost in all the forum postings.

Really nice!!

I ran it under Linux with wine, that worked just fine, by the way.

I was wondering, do you use raycast-based wheels or actual wheels as rigidbodies with constraints?

Best regards,
Ola

Thanks, can you try out Bullet 2.75 RC2?

Yes, it works fine now! Thank you.

I just tested the RC1 (svn 1691), and I think I might have a problem with static rigid bodies. We depend on switching the rigid bodies from dynamic to static and back (by removing, re-adding with or without mass). Previous behaviour for these was that they are added to the world and show up as activ...

Just a small reminder for this tiny fix
http://www.bulletphysics.com/Bullet/php ... f=9&t=3599

(virtual definition of addCollisionObject / removeCollisionObject in btCollisionWorld.h)

Best regards,
Ola

Small update, I made a patch with a fix suggestion, see the issue tracker.

I ran into weird problems with my own raycast-based vehicle recently, and just found the reason why. Some assets in my game world are static mesh shapes, rotated within a compound shape. Raycasts hitting these objects return normal vectors that don't seem to take the child shape rotation into accoun...

Sounds like you get some penetration between the sphere and platform initially before their speeds match. If you know the sphere is resting on the platform, try setting it's linear velocity to the same as the platform when starting to move the platform. Alternatively, maybe you can try to slowly ram...